1. Field of the Invention
The invention relates to intelligent data storage systems. The invention further relates to scheduling systems that provide intelligent data storage systems with the ability to perform actions on a scheduled or event driven basis.
2. Background Art
An intelligent data storage system needs the ability to perform actions on a scheduled or event driven basis. Sequencing of related activities must be enforced. Error monitoring and recovery must be performed. Activities must sometimes be performed on a periodic basis and sometimes be performed just once. Information must be available about past, present, and future activities.
In addition, a scheme for prioritization of activities must be provided. An activity must be interruptible so that a higher priority activity can be run.
Further, resources must be managed. Activities must be able to reserve resources, and activities must only be started when adequate resources are available.
While there are numerous existing scheduling systems, ranging from something as simple as UNIX cron to commercial systems, such as JES3, these systems do not provide the combination of activity scheduling, sequencing, monitoring, and error recovery needed to provide an autonomous storage system.
Background information may be found in U.S. Pat. Nos. 5,504,858; 6,272,606; 6,304,948; 6,675,176; and 6,801,992; and in U.S. Patent Application Publication Nos. 2001/0039576 A1, 2002/0174295 A1, 2003/0115204 A1, 2003/0145270 A1, 2003/0237019 A1, 2004/0163009 A1, 2004/0205206 A1, 2004/0243699 A1, 2004/0250249 A1, and 2004/0267916 A1.